Not content to rest with this innovation, SMIT attaches them in such a way that they can flutter like actual leaves. Each solar leaf is attached to a piezoelectric generator; the shaking of the leaf generates an extra bit of power.

The leaf idea is also being used in the creation of biologically-based artificial leaves that can also harvest solar energy. At Arizona State University, Tom Moore and his co-workers are using artificial cell like structures called liposomes as light harvesting machines.

Chloroplasts do not convert sunlight into electrical current. They merely move electrons from one side of a membrane to another - a process that is eventually exploited to make chemicals. It would be a very useful ability to mimic in artificial systems: imagine chemicals factories where the reactions are not driven by, say, heat from a flame, but directly from the energy of sunlight. This is the kind of vision that Moore’s group is pursuing.

The Gratzel cell produces elecromotive force (EMF), which is exactly what is needed to run the motors and electronic devices of the macroscopic world. But in a chloroplast, electron transfer has a different result. It leads to an electrochemical potential that drives microscopic motors and other devices of living cells. Electron transfer in chloroplasts occurs inside complex membrane structures. They are made from a collection of molecules called “phospholipids” - molecular “tadpoles” with a water soluble head group and a water insoluble tail. In water, phospholipids spontaneously form hollow spherical membranes called liposomes, driven by the tendency of the insoluble tail to shy away from the water.

Thomas A. Easton had a very similar idea in his 1990 novel Sparrowhawk. He imagined that plants could be genetically altered in such a way that the individual cells on a leaf could be activated in different colors - a leaf screen that could be grown by the thousands.